Hi All,
I have a 2005 FX4 with the 4r75E transmission.

I get what feels like something is binding and then lets go when I first start off in reverse or first gear. It happened occasionally and now happens after being driven for about 10-20 miles consistently. Now it will buck a few times from start and and I hear the engine run freely between bucks. Fluid looks beautiful and no burnt smell. So far the bucking problem happened twice and it's now parked.

At first I thought it was a limited slip differential problem at first but I eliminated that by changing the gear oil, friction modifier and inspecting the LS clutches.

There are no other shifting problems. Could it be the valve body?

Any help at all would be greatly appreciated.

Thanks,
Andy